yielding \(\mathbf {T}^{2}\)  corrections in the principle of
\(f(\mathcal {G})\)  theory initially proposed in
[1]}. Here, we discuss the quadratic form of
the functional defined as \(\mathfrak {g}_{2}(\mathbf {T}^{2})=\eta \mathbf {T}^{2}\) . Therefore, Eq.(REF ) takes the following form
\(f(\mathcal {G},\mathbf {T}^{2})=\mathfrak {g}_{1}(\mathcal {G})+\eta \mathbf {T}^{2},\) 
